Initial release of lock/ unlock operation in MiscService

src/main/java/net/brutex/xservices/util/LockCleanerJob.java

@@ -0,0 +1,51 @@
+package net.brutex.xservices.util;
+
+import java.sql.*;
+import java.time.Instant;
+import java.util.concurrent.atomic.AtomicBoolean;
+import lombok.extern.slf4j.Slf4j;
+import org.h2.jdbcx.JdbcConnectionPool;
+import org.quartz.*;
+
+@Slf4j
+@DisallowConcurrentExecution
+public class LockCleanerJob implements Job, InterruptableJob {
+
+    private final AtomicBoolean isInterrupted = new AtomicBoolean(false);
+
+    @Override
+    public void execute(JobExecutionContext context) throws JobExecutionException {
+        log.debug("LockCleaner is executing now.");
+        final Instant d = Instant.now();
+        final long ts = d.toEpochMilli();
+        final JdbcConnectionPool mpool = (JdbcConnectionPool) context.getMergedJobDataMap().get("mdbConnection");
+        final String deleteMemTable = "DELETE FROM brutex.tbl_lock where btx_validity < " + (ts-5000);
+
+        try (Connection mcon = mpool.getConnection()){
+            Statement stmt = mcon.createStatement();
+            stmt.execute(deleteMemTable);
+            int count = stmt.getUpdateCount();
+            log.debug("LockCleaner deleted '{}' stale locks.", count);
+
+        } catch (SQLException e) {
+            log.error("Exception in SQL execution: {}", e.getMessage());
+            throw new JobExecutionException(e);
+        }
+    }
+
+
+        /**
+     * <p>
+     * Called by the <code>{@link Scheduler}</code> when a user
+     * interrupts the <code>Job</code>.
+     * </p>
+     *
+     * @throws UnableToInterruptJobException if there is an exception while interrupting the job.
+     */
+    @Override
+    public synchronized void interrupt() throws UnableToInterruptJobException {
+        isInterrupted.set(true);
+        log.warn("LockCleanerJob received an interrupt.");
+        Thread.currentThread().interrupt();
+    }
+}

src/main/java/net/brutex/xservices/util/MiscServiceServletContextListener.java

@@ -185,6 +185,8 @@ public class MiscServiceServletContextListener implements ServletContextListener
         if(configuration.getCleaner_interval()>0) {
             startEventLogCleaner((Scheduler) context.getAttribute("scheduler"));
         }
+
+        startLockCleaner((Scheduler) context.getAttribute("scheduler"));
     }
 
     private String getLinkSQL() {
@@ -235,6 +237,31 @@ public class MiscServiceServletContextListener implements ServletContextListener
         }
     }
 
+    private void startLockCleaner(Scheduler scheduler) {
+        try {
+            if (!scheduler.checkExists(JobKey.jobKey("LockCleaner"))) {
+                JobDetail job2 = JobBuilder.newJob(LockCleanerJob.class).withIdentity("LockCleaner").build();
+                job2.getJobDataMap().put("mdbConnection", mempool);
+        SimpleTrigger t =
+            (SimpleTrigger)
+                newTrigger()
+                    .withIdentity("LockCleaner")
+                    .withSchedule(
+                        SimpleScheduleBuilder.simpleSchedule()
+                            .withIntervalInMinutes(2)
+                            .repeatForever())
+                    .startAt(
+                        Date.from(
+                            Instant.now()
+                                .plus(2, ChronoUnit.MINUTES)))
+                    .build();
+                scheduler.scheduleJob(job2, t);
+            }
+        } catch (SchedulerException ex) {
+            log.error("Could not start LockCleaner: {}", ex.getMessage());
+        }
+    }
+
     private void readConfiguration(ServletContext ctx) {
                 /* Configure ServletContext attributes using configuration object*/
                 EventmanagerConfiguration c = EventmanagerConfiguration.getInstance().refreshConfig();

src/main/java/net/brutex/xservices/ws/MiscService.java

@@ -72,7 +72,14 @@ public interface MiscService {
 	  @WebMethod(operationName="lock")
 	  @WSDLDocumentation("Get a lock.")
 	  public abstract BigInteger lock(@WebParam(name="id") @XmlElement(nillable = false) String id,
-									  @WebParam(name="objectId") @XmlElement(nillable = false) String objectId) throws XServicesFault;
+									  @WebParam(name="objectId") @XmlElement(nillable = false) String objectId,
+									  @WebParam(name="validity") BigInteger validity) throws XServicesFault;
+
+	@WebMethod(operationName="unlock")
+	@WSDLDocumentation("Remove a lock.")
+	public abstract Boolean unlock(		@WebParam(name="id") @XmlElement(nillable = false) String id,
+									    @WebParam(name="objectId") @XmlElement(nillable = false) String objectId)
+									    throws XServicesFault;
 
 	 @WebMethod(operationName="", action = "EventNotice")
 	 @SOAPBinding(use = SOAPBinding.Use.LITERAL, style = SOAPBinding.Style.DOCUMENT, parameterStyle = SOAPBinding.ParameterStyle.BARE)

src/main/java/net/brutex/xservices/ws/impl/MiscServiceImpl.java

@@ -63,6 +63,7 @@ import org.quartz.*;
 public class MiscServiceImpl
         implements MiscService {
 
+    final Object serializedDbAccess = new Object();
     @Resource
     private WebServiceContext context;
 
@@ -167,58 +168,83 @@ public class MiscServiceImpl
         return new RuntimeInfoType();
     }
 
+
     @Override
-    public BigInteger lock(String id, String objectId) throws XServicesFault {
+    public Boolean unlock(String id, String objectId) throws XServicesFault {
-
+        MessageContext cont = context.getMessageContext();
-
+        final ServletContext servletContext =
-        final String conString = "jdbc:h2:mem:lockdb;DB_CLOSE_DELAY=10;" +
+                (ServletContext) cont.get(MessageContext.SERVLET_CONTEXT);
-                "INIT=CREATE SCHEMA IF NOT EXISTS brutex\\;" +
+        final JdbcConnectionPool pool = (JdbcConnectionPool) servletContext.getAttribute("mdbConnection");
-                // "SET SCHEMA brutex\\;" +
+        try(Connection con = pool.getConnection()) {
-                "CREATE SEQUENCE IF NOT EXISTS brutex.btx_sequence1\\;" +
+            PreparedStatement prep = con.prepareStatement("DELETE FROM brutex.tbl_lock where btx_id = ? AND btx_obj_id = ?");
-                "CREATE TABLE IF NOT EXISTS brutex.tbl_lock (btx_seq BIGINT NOT NULL, btx_id VARCHAR(100) NOT NULL, btx_obj_id VARCHAR(100) NOT NULL, btx_timestamp BIGINT NOT NULL);";
-
-        //JdbcConnectionPool cp = JdbcConnectionPool.create(conString, "sa", "");
-        //cp.setMaxConnections(1);
-
-        Connection con = null;
-        long rows = 0L;
-        final long ts = new Date().getTime();
-        try {
-            Class.forName("org.h2.Driver"); //Java 1.8
-            con = DriverManager.getConnection(conString);
-            PreparedStatement prep = con.prepareStatement(
-                    "SELECT btx_id from brutex.tbl_lock where btx_obj_id=? ORDER BY btx_seq DESC");
-            prep.setString(1, objectId);
-
-            ResultSet rs = prep.executeQuery();
-            StringBuffer bf = new StringBuffer();
-            while (rs.next()) {
-                //bf.append(rs.getString(1));
-                rows++;
-            }
-            rs.close();
-
-            prep = con.prepareStatement("INSERT INTO brutex.tbl_lock values (NEXT VALUE FOR brutex.btx_sequence1, ?, ?, ?)");
             prep.setString(1, id);
             prep.setString(2, objectId);
-            prep.setLong(3, ts);
             prep.execute();
-
+            if(prep.getUpdateCount()>0) return Boolean.TRUE;
-            prep = con.prepareStatement("DELETE from brutex.tbl_lock WHERE btx_timestamp < ?");
+        } catch (SQLException e) {
-            prep.setLong(1, ts - 10000);
-            prep.execute();
-            prep.close();
-
-            con.close();
-            //System.out.println(bf);
-        } catch (SQLException | ClassNotFoundException e) {
             throw new XServicesFault(e);
         }
+        return Boolean.FALSE;
+    }
+    final Object lockObj = new Object();
+    @Override
+    public BigInteger lock(String id, String objectId, BigInteger validity) throws XServicesFault {
 
+        MessageContext cont = context.getMessageContext();
+        final ServletContext servletContext =
+                (ServletContext) cont.get(MessageContext.SERVLET_CONTEXT);
+
+        if(validity == null || validity.longValue()<0) validity = BigInteger.valueOf(60000*60*12);
+
+        final JdbcConnectionPool pool = (JdbcConnectionPool) servletContext.getAttribute("mdbConnection");
+        final long ts = Instant.now().toEpochMilli();
+        final long validUntil = ts + validity.longValue();
+
+        long rows = 0L;
+
+    try (Connection con = pool.getConnection()) {
+        PreparedStatement prep =
+                con.prepareStatement(
+                        "SELECT btx_id from brutex.tbl_lock "
+                                + " where btx_obj_id = ? "
+                                + " AND btx_validity >= ? ORDER BY btx_seq asc");
+        PreparedStatement prep2 = con.prepareStatement(
+                        "INSERT INTO brutex.tbl_lock values (NEXT VALUE FOR brutex.btx_sequence1, ?, ?, ?, ?)");
+        prep.setString(1, objectId);
+        prep.setLong(2, ts);
+
+        prep2.setString(1, id);
+        prep2.setString(2, objectId);
+        prep2.setLong(3, ts);
+        prep2.setLong(4, validUntil);
+
+        ResultSet rs;
+        synchronized (lockObj) {
+            rs = prep.executeQuery();
+            if (rs.next()) {
+              /* lock already set and first in queue */
+              String lock_id = rs.getString(1);
+              if (lock_id.equals(id)) {
+                /* return directly from here */
+                return BigInteger.ZERO;
+              }
+              rows = 1;
+              while (rs.next()) {
+                /* count but not self. Using DB COUNT(*) might be faster */
+                if (!rs.getString(1).equals(id)) rows++;
+              }
+            }
+            /* lock not found, need to insert */
+            prep2.execute();
+        }
+
+    } catch (SQLException e) {
+        log.error("Error during 'lock' operation. SQL error: {}", e.getMessage());
+            throw new XServicesFault(e);
+    }
         return BigInteger.valueOf(rows);
     }
 
-    final Object serializedDbAccess = new Object();
     @Override
     public ALFEventResponseType mergeALFEvent(ALFEventType event) throws XServicesFault {
         final Instant d = Instant.now();

src/main/resources/ddl/BRTX_schema.ddl

@@ -55,3 +55,16 @@ CREATE CACHED TABLE IF NOT EXISTS brutex.tbl_events_all
 
 CREATE INDEX IF NOT EXISTS brutex.btx_idx_ssed ON brutex.tbl_events_all (btx_supersed_id);
 CREATE INDEX IF NOT EXISTS brutex.btx_idx_ts ON brutex.tbl_events_all (btx_timestamp ASC);
+
+-- MiscService lock operation
+CREATE SEQUENCE IF NOT EXISTS brutex.btx_sequence1;
+CREATE TABLE IF NOT EXISTS brutex.tbl_lock (
+    btx_seq BIGINT NOT NULL,
+    btx_id VARCHAR(100) NOT NULL,
+    btx_obj_id VARCHAR(100) NOT NULL,
+    btx_timestamp BIGINT NOT NULL,
+    btx_validity BIGINT NOT NULL
+);
+
+--CREATE INDEX IF NOT EXISTS brutex.btx_idx_seq ON brutex.tbl_lock (btx_seq ASC);
+--CREATE INDEX IF NOT EXISTS brutex.btx_idx_key ON brutex.tbl_lock (btx_obj_id, btx_validity DESC);